The pilots of AirAsia Flight 8501 cut power to a critical computer
system that normally prevents planes from going out of control shortly
before it plunged into the Java Sea, two people with knowledge of the
investigation said.According to Bloomberg,the
action appears to have helped trigger the events of Dec. 28, when the
Airbus Group NV A320 climbed so abruptly that it lost lift and it began
falling with warnings blaring in the cockpit, the people said. All 162
aboard were killed.

The pilots had been attempting to deal with alerts about the flight
augmentation computers, which control the A320’s rudder and also
automatically prevent it from going too slow. After initial attempts to
address the alerts, the flight crew cut power to the entire system,
which comprises two separate computers that back up each other, the
people said.While the information helps show how a normally functioning A320’s
flight-protection system could have been bypassed, it doesn’t explain
why the pilots pulled the plane into a steep climb, the people said.
Even with the
computers shut off, the pilots should have been able to fly the plane manually, they said.

Airbus discourages pilots from cutting power to systems because
electronics in the highly computerized aircraft are interconnected and
turning off one component can affect others, John Cox, a former A320
pilot who is now a safety consultant, said in an interview.

The latest insight into what could have led to the AirAsia plane’s crash
comes as it was revealed the co-pilot was actually at the controls of
the doomed flight just before it plunged into the ocean.

Indonesia’s lead investigator said the Airbus, which was less than
halfway into a two-hour flight from the Indonesian city of Surabaya to
Singapore when it disappeared, was being piloted by second-in-command
Remi Plesel.

He was flying Flight QZ8501 prior to it crashing into the sea, not Captain Iriyanto – an experienced former military jet pilot